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UDC 628.35.004.4
Noskova I. A., Bazhenov V. I., Epov A. N.
The use of simulation modeling packages for wastewater treatment technologies
Summary
The subjects of the study were: comparative analysis of software packages for simulation modeling of wastewater treatment processes to manage design and operation issues; and also assessment of basic data for the formation of mathematical model inputs. The basic parameters of the description of the most complicated ASM activated sludge models have been analyzed. The results of the studies are represented by the analysis of the examples: distribution of COD fractions under local conditions of Russia and some other countries; typical irregularity of wastewater flow and basic pollutants hourly input; design and measured oxygen uptake rate (OUR); model time calibration process, optimization of the denitrification zone in aeration tank for MUCT process. The analysis of the advanced software defined GPS-X (Hydromantis, Canada) design software as the most complete and comprehensive product. The suggested technique includes a set of measures: determining COD fractionation with the use of OxiTop (WTW, Germany) analyzer; assessment of basic parameters of irregular basic pollution mass input; respirometry studies; statistic processing of data obtained at the facilities. In the process of simulation modeling the hydrodynamic structure of the wastewater treatment facilities appears as series-connected mixer chambers. The number of chambers is assigned depending on the length and width of the facility, flow velocity, mixing rate, availability of internal baffles, and also inner recycle streams. The simulation model provides for the optimization of the following parameters: zone ratio in the aeration tank, sludge age, dissolved oxygen concentration, recycle ratio values, as well as the parameters of the automatic control system.
Key words
wastewater , biological treatment , mathematic modelling , ASM models , simulation modeling , GPS-X software
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UDC 628.35:004.69
Egorova Yu. A., Levin D. I., Liushina L. F., Petropavlovskii S. A., Bazhenov V. I., Danilovich Dmitrii, Noskova I. A.
Integrated upgrade of the Samara municipal wastewater treatment facilities
Summary
The experience of «Samarskie Kommunal’nye Sistemy» LLC in designing, constructing and upgrading the municipal wastewater treatment facilities with a capacity of 450–750 thousand m3/day is presented. Considering the adverse ecological state of the midstream and downstream of the Volga River the task of improving the efficiency of wastewater treatment is of top priority that has been approved by the Program adopted by the Department of Energy and Public Utilities of the Samara Area for 2013–2019. The results of retrofitting wastewater biological treatment technology on the basis of UCT Process with unique zone and recycling layout barrangement by modifying the existing capacities of four-corridor aeration tanks are presented. The justified technical solutions of the key facilities that determine the energy and structural efficiency of the project of upgrading the air blower house with the use of mechanically regulated air blowers (the capacity range of each 59.4–132.1 thousand Nm3/h) and constructing two sludge pumping stations with 15000–27360 m3/h regulated wastewater flow are set. The process automated control system has been introduced. The tied to time design works required fast and efficiency calculation methods with the use of process simulation modeling in GPS-X environment (ASM2d model), computerized fluid dynamics – in ANSYS Fluent environment. The prediction of the dynamics of the treatment efficiency changing within 24 hours while ensuring average daily concentrations in mg/l – suspended solids – 15.5; BOD5 – 5.7; COD – 34.9;
N–NH4 – 0.25; N–NO2, N–NO3 – 7.02; P–PO4 – 0.68 is given. Relatively high washout of suspended solids is caused by the significant design value of sludge index 150 сm3/g. In the implementation phase of the environmentally efficient measures the construction of tertiary treatment facilities valued at 400 million rubles (about 30% of the total cost of the upgrade of the entire facilities) was rendered economically unviable. Before commissioning the actual energy saving of 13 mln kW·h/year including 8.8 mln kW·h/year owing to the replaced air blowers, 4.2 mln kW·h/year owing to the sludge pumping stations with submerged pumps that replaced airlift was achieved. The performance targets of the projects and the technical solutions applied measure up to the best available technologies.
Key words
reconstruction , energy efficiency , best available techniques , aeration tank , simulation modeling , wastewater treatment facilities , UCT process , GPS-X
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UDC 628.35
DOI 10.35776/VST.2024.12.05
Рожков В. С., Нездойминов В. И., Vasil’eva Iuliia
Simulation of biological wastewater treatment systems
with simultaneous nitri-denitrification using ASM3P-2SND
(for discussion)
Summary
The issues of mathematical simulation of biological wastewater treatment systems with activated sludge based on empirical equations are considered. It is noted that the available approaches to simulation technique have shortcomings that complicate describing biological processes with activated sludge at the facilities with simultaneous nitri-denitrification. An improved mathematical model ASM3P-2SND for municipal wastewater treatment with activated sludge is proposed. This model takes into account in addition the transformations of phosphorus compounds during the activities of autotrophs and heterotrophs, describes the mutual transformations of oxidized forms of nitrogen – nitrates and nitrites; besides, it can also be adapted to consider the diffusion limitations of substrate and oxygen penetration into activated sludge flocs in bioreactors with simultaneous nitri-denitrification. The convergence test, adjustment and calibration of the proposed model were performed at the operating facilities with simultaneous nitri-denitrification, as well as in pilot conditions of wastewater treatment in airlift bioreactors. It was found that the proposed ASM3P-2SND model of activated sludge adequately describes the processes of biological treatment with simultaneous nitri-denitrification and is capable of accounting for the diffusion limitations of oxygen and dissolved substrate penetration into activated sludge flocs. The dependence of the diffusion limitation coefficients proposed for the adaptation of the model on the size of activated sludge flocs was qualitatively established.
Key words
biological treatment , simultaneous nitri-denitrification , activated sludge , simulation modeling , ASM3P-2SND model
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UDC 628.356.1:621.61
Bitiev A. V., Basov N. S., Novikov S. N., Smolenskii A. V., Ustiuzhanin A. V., Bazhenov V. I.
Predicting energy-efficient effect of the controlled air delivery
at the Novo-Liuberetskie Wastewater Treatment Facilities
Summary
Стратегия развития АО «Мосводоканал» предусматривает
The corporate strategy of «Mosvodokanal» JSC envisages the systematic practical application of energy-efficient solutions substantiated by the method of mathematical prediction of the energy-efficient effect of the controlled air delivery at the air blower house of Block No. 1 of the Novo-Liuberetskie Wastewater Treatment Facilities in Moscow. The controlled air delivery to the aeration tanks for the biological wastewater treatment processes has been proposed as a key and cost effective method of energy conservation. The energy-efficient effect was determined by comparing the resultant energy consumption of two states of the predictable air deliver system – the basic state without control and controlled one. In the process of data and measurement method generation the calibrated metering devices of the operating SCADA system and data of the certified laboratory were used. The experimental survey of the air blower house with N750-23-6 units was carried out. The average decrease of air delivery resulting from the equipment deterioration for the 35 years’ operating period was 5.8–10.4%; the operation pressure decrease was 40.7–5.4%. The isoentropic coefficient of performance of N750-23-6 units was 75% at 79% rating. The method of predicting the energy-efficient effect including the mathematical model of energy input is considered. The model provided for 1.27% average ratio error at the verification against the actual environment of the operating object. The mathematical prediction of the energy-efficient effect revealed 32.5% or 11,343.97 thousand kWh/year reserve or 30,061.52 thousand ruble/year (VAT excluded) savings. Adjustable blade control of the air blowers was chosen as the technical basis of the energy efficiency. The study results formed the basis for the energy service contract.
Key words
energy efficiency , control arrangements , sewerage treatment facilities , simulation modeling , air-blowing house , rotary blade regulation , energy service contract , energy-efficient effect
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UDC 628.356.1:621.61
Rakitskii D. S., Egorova Yu. A., Levin D. I., Gordeev S. A., Nagornyi S. L., Bazhenov V. I., Petrov V. I., Ustiuzhanin A. V.
Energy-efficient principle of upgrading the air blower house at the Samara municipal wastewater treatment facilities
Summary
As a key and economically advantageous measure on energy efficiency and investment return in the field of wastewater disposal «Samarskie Kommunal’nye Sistemy» Company approves the processes of air supply regulation at the municipal wastewater treatment facilities. A big complex of the air blower house has been designed and successfully implemented by improving the typical design projects for the RF conditions developed by SoiuzvodokanalNIIproject Institute for the estimated supply of 132 144 Nm3/h. The specific features of building and assembly works when installing 15 ton units under the conditions of the limited capacity of the hoisting equipment (9 tons) are set. The mechanical rotary blade principle of fan regulation was adopted as a basis of the energy saving solution. At the first implementation stage under the conditions of the lack of an operating automated process control system 26.1% reduction of the specific power consumption was recorded at the average specific power consumption of 22.39 kW/1000 Nm3. The engineering design reflects possible 45–100% regulation of air supply to the aeration tanks as well as its relation to the consumed power of 1273.2–2674.2 kW (for 20 °C input temperature, 50% relative humidity). Two-loop scheme of the automated control system for «aeration tank gate valve control unit – blower unit group» is presented. The analysis of the fan testing at the manufacturer’s factory is given. The parameters of regulating centrifugal air blowers by two control actions: of regulated diffuser at the outlet and inlet guide vane unit are presented. The mathematical method of recalculating the characteristics of air blowers with the use of the «degree of control» basic concept was developed and experimentally verified. The use of the method proves the wide range of the running characteristics of regulated units for all the year seasons, the mode of combined operation of one non-regulated and three regulated air blower units for the experimental work period.
Key words
reconstruction , energy efficiency , simulation modeling , air-blowing house , wastewater treatment facilities , rotary blade regulation
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